Many forms of electronic apparatus are mounted in a casing having side walls, top and bottom walls, and a front panel which carries control elements, such as switches, and condition indicating elements, such as gauges and indicator lamps. The casing is closed at the rear, i.e. opposite the front panel, by a backplane. The backplane is fitted to the casing when the various components of the apparatus have been assembled and placed in position inside the casing. The backplane serves several purposes. For example, the backplane prevents stray material from entering the interior of the casing and possibly causing damage to the electronic apparatus, and also shields the user of the apparatus from unintended contact with components located inside the casing. In addition, the backplane generally carries connector receptacles whereby connection is made between the apparatus and external cables.
The backplane itself usually performs an interconnect function within the apparatus, and may be constructed as a printed circuit board. That is to say, the backplane is made of dielectric material and carries at least one run or trace of electrolessly deposited metal that has been etched to a predetermined pattern and to which connection to different components of the apparatus is made at at least two locations. The circuit board may have a single layer of metal within which the traces are delineated, or it may have multiple layers of dielectric material laminated together and each carrying a layer of conductive material that forms one or more circuit traces.
It is also common for electronic apparatus to include so-called interior backplanes or mother boards which perform similar electrical functions to the backplane proper but are not located at the exterior of the apparatus and therefore are not accessible to the user of the apparatus in normal operation. Such an interior backplane is used as an interconnect element inside the apparatus.
One problem associated with conventional backplanes is that connection of conductors to the circuit runs of the backplane typically involves a soldering operation or use of compliant-pin, press-fit connector technology. Generally, a backplane has multiple circuit runs, and it is desired to connect the conductors of a ribbon cable or other multiple conductor cable to the conductor runs of the backplane. The connection must generally be detachable, and this has hitherto involved providing the cable with a detachable connector receptacle, such as a receptacle of the kind used on flat, flexible ribbon cables, and attaching the header portion of the connector to the backplane. The individual connector elements of the header may be connected to the circuit runs of the backplane by a hand soldering operation. It is not viable using current technology to use automatic soldering techniques for connecting the circuit runs to the conductive elements of the header portion of the connector. Compliant-pin, press-fit connector technology alleviates soldering problems, but use of existing components suitable for installation in backplanes for the purpose of facilitating electrical connections to the interior of the apparatus poses a second problem.
This second problem associated with making electrical connections to the interior of the apparatus from a rear backplane is that the operation of installing connector headers using either solder techniques or existing compliant-pin, press-fit technology causes the conductive elements (pins) of the headers to extend through to the outside surface of the backplane, thereby exposing the apparatus to potential damage by inadvertent earthing or shorting of the pins of the header by a careless user or by other accident. Further, such practices provide a potential hazard to users of the apparatus by exposing them to circuit voltages, emissions or other hazards associated with exposed electrical connections.